The image site is the home of LOLcats and thousands of other, less pleasant, internet images. The boards cover bizarre Japanese animation along with other rather niche adult content.

But apart from hosting weird tentacle porn the site is also home to what are now very angry hackers. Sarah Palin's emails first surfaced on the site and its boards were an early focus for the Anonymous anti-Scientology protest group, so they are not a group with whom to mess.

A 4chan admin called 'moot' said on Sunday that AT&T were filtering or blocking the site. Moot asked AT&T customers to call the telco to complain. He said no one from AT&T had contacted 4chan.

There has been no official comment yet from AT&T - we're waiting to hear back from US PRs. It is possible that an image on the site has triggered a child sex abuse filter at the telco which led to the automatic blocking of the site. That might not be enough to satisfy the anger of 4chan users. ®